Organic electroluminescence (organic EL) elements are characterized by the capability of operating at a low voltage of several volts to tens of volts, wide angle of visibility and high visibility due to the self-luminescent property, and being complete solid-state elements in the form of a thin film. Because of these characteristics, organic EL elements are beginning to become popular in the market. For example, they are used for displays and lighting equipment, and are also used for main displays of mobile phones in terms of space-saving, energy-saving and portability. In recent years, there has been an increasing demand for large-area organic EL panels used for lighting equipment or displays.
However, there are problems with manufacturing large-area organic EL panels, such as the large size of the apparatuses therefor, degraded brightness distribution and low yield.
To cope with these problems, tiling techniques of piecing small-area organic EL panels together have been proposed.
For example, Patent Document 1 discloses a technique of arranging organic EL panels in a step-like shape such that a transparent substrate part of an organic EL panel is laid on a display part of another organic EL panel. This configuration enables provision of a display apparatus that does not have any non-luminescent area. However, Patent Document 1 does not describe any specific manner for arranging organic EL panels such as adhesion and wiring between them. Further, since the light emitting panel has a not rectangular but uneven outer shape, it was found that there are difficulties, for example, in incorporation into lighting equipment.
Patent Document 2 discloses a technique of mounting a plurality of organic EL panels on a holder plate and inserting opposing two sides of organic EL elements in holding grooves of the holder plate to fix them. Each of the organic EL panels has a connector for connecting an electrode to an outer terminal, and is connected to the outer terminal by the connector being inserted in a connection hole of the holder plate. However, considering the possibility of outdoor use as well as indoor use, it was found that this technique cannot achieve sufficient levels of strength, moisture resistance and drip-proof performance.